Plants of the scrub
Because montane scrub has almost disappeared from Scotland, many of the plants associated with it are also rare, including several of the montane willows. Woolly willow is so rare as to feature in the Red Data Book of threatened plants (see box), and several other montane species listed are officially recorded as scarce. Although juniper is more widespread, it has declined greatly in parts of its range and is under severe management pressure elsewhere, with scarcely any regeneration occurring at many of its sites. Both juniper and mountain willows are the subjects of Biodiversity Action Plans, published by the Government and the Scottish Executive, aimed at encouraging their conservation.
Woolly willow in trouble
Of 14 populations of woolly willow known in 1996, just five were large enough to have any chance of surviving in the long term. A survey showed that three of the other populations were apparently extinct, and three had been reduced to just a single female plant. Like all willows, woolly willow grows as separate male and female plants. It cannot reproduce unless the two sexes grow within about 50 metres of each other, to allow for effective pollination. It also needs bare ground, free from grazing, in which its seeds can germinate.
Because the remaining montane scrub in Scotland consists of just scattered bushes, the ground flora associated with it is impoverished or much suppressed. However, areas of 'subalpine scrub' on the continent give an idea of what the restored habitat in Scotland could look like. They often include attractive displays of wood cranesbill (Geranium sylvaticum), globeflower (Trollius europaeus) and a range of other 'tall herbs' which today are found in Scottish mountains only on inaccessible rock ledges.
The shelter and humidity also provide a habitat for ferns, mosses and lichens that otherwise would be restricted to shady gorges on the hillside.
One particularly attractive (and currently very rare) species that would benefit from the restoration of montane scrub is alpine sowthistle (Cicerbita alpina). All the evidence suggests that in Scotland this was once a plant of high altitude birch woods, as it still is on the continent.
alpine sowthistle
However, it is now on the very edge of extinction here because of the drastic decline in these birchwoods and increased grazing by sheep and red deer. (It is a highly edible plant that is still eaten by the Sami people of northern Scandinavia, as 'Lapp Lettuce').
Today this tall, spectacular plant is confined to just four sites in the Highlands, on rock ledges beyond the reach of hungry deer and sheep. Through its Species Action Programme, Scottish Natural Heritage is working to protect the plant, but only a significant restoration of its montane scrub habitat will secure the sowthistle's future.